The present invention provides a multilayer body of an inorganic substrate and a highly heat-resistant transparent film which has sufficient heat resistance and is able to be mechanically separated from the inorganic substrate after being subjected to various processes on the inorganic substrate since the adhesion between the highly heat-resistant transparent film and the inorganic substance is adequately weak. A multilayer body of a highly heat-resistant transparent film and an inorganic substrate, wherein: an adhesive is not substantially used; the peel strength between the highly heat-resistant transparent film and the inorganic substrate is 0.3 N/cm or less; and the CTE of the highly heat-resistant transparent film is 50 ppm/K or less.

The present invention relates to a method for manufacturing a polyimide-powder composite separator using water and a polyimide-powder composite separator manufactured by the method, and is environmentally friendly since an organic solvent is not used in the overall process of manufacturing the composite separator and has advantageous effects in terms of time, cost, and manufacturing process since a high temperature/high pressure environment is not required.

A poly(etherimide) includes repeating units derived from polymerization of a biphenol dianhydride and an organic diamine. A method of making the poly(etherimide) includes contacting the biphenol dianhydride and the organic diamine under conditions effective to provide a poly(etherimide). The poly(etherimide) can be useful in a variety of articles, for example in an optoelectronic component.

The present invention is a substrate for a display, the substrate having a film B including a polysiloxane resin on at least one surface of a film A including a polyimide resin, wherein the film B contains inorganic oxide particles therein, and the present invention has an object to provide a substrate for a display: being able to be applied to a color filter, an organic EL element, or the like without the need to carry out any complex operations; allowing high-definition displays to be manufactured; and being provided with a low CTE, a low birefringence, and flexibility.

The present disclosure provides a low-dissipation flexible copper clad laminate, which includes a copper foil and a polyimide film. The polyimide film is attached to the copper foil. The polyimide film includes a polyimide, and the polyimide has a structure represented by formula (I). Formula (I) is defined as in the specification.

The present invention provides a tetracarboxylic acid diester compound shown by the following general formula (1),

##STR00001##

wherein X.sub.1 represents a tetravalent organic group; and R.sub.1 represents a group shown by the following general formula (2),

##STR00002##

wherein the dotted line represents a bond; Y.sub.1 represents an organic group with a valency of k+1; “k” represents 1 or 2; and “n” represents 0 or 1. There can be provided a tetracarboxylic acid diester compound that can give a polyimide precursor polymer soluble in a safe organic solvent widely used as a solvent of a composition and usable as a base resin of a photosensitive resin composition.

Disclosed is a net-shaped polyimide sponge. The polyimide sponge has a stack structure of nets. Also disclosed is a method for producing a polyimide sponge. The method enables the production of a polyimide sponge in a continuous process, which offers advantages for large-scale production compared to conventional methods using batch systems.

A polyamic acid useful for forming a protective or insulative layer for semiconductor elements has a structure represented by chemical formula (1): ##STR00001##
wherein δ represents an oxygen or sulfur atom; W represents an electron-withdrawing group; and R.sup.11 and R.sup.12 represent independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent, and a solvent is provided. The dissolvable polyimide is represented by formula 1:

##STR00001##

wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≦X≦0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A dry phase inversion process is performed on the polyimide membrane.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1:

##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≦X≦0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.